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KVM: x86: Reset MMU context if guest toggles CR4.SMAP or CR4.PKE 

[ Upstream commit 8d214c4816 ]

Reset the MMU context during kvm_set_cr4() if SMAP or PKE is toggled.
Recent commits to (correctly) not reload PDPTRs when SMAP/PKE are
toggled inadvertantly skipped the MMU context reset due to the mask
of bits that triggers PDPTR loads also being used to trigger MMU context
resets.

Fixes: 427890aff8 ("kvm: x86: Toggling CR4.SMAP does not load PDPTEs in PAE mode")
Fixes: cb957adb4e ("kvm: x86: Toggling CR4.PKE does not load PDPTEs in PAE mode")
Cc: Jim Mattson <jmattson@google.com>
Cc: Peter Shier <pshier@google.com>
Cc: Oliver Upton <oupton@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923215352.17756-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5.4-rM2-2.2.x-imx-squashed
Sean Christopherson 2020-09-23 14:53:52 -07:00 committed by Greg Kroah-Hartman
parent 87f7a4910e
commit 16788dc19f
1 changed files with 2 additions and 1 deletions
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3
arch/x86/kvm/x86.c
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@ -973,6 +973,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
unsigned long old_cr4 = kvm_read_cr4(vcpu);
unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE |
X86_CR4_SMEP;
unsigned long mmu_role_bits = pdptr_bits | X86_CR4_SMAP | X86_CR4_PKE;
if (kvm_valid_cr4(vcpu, cr4))
return 1;
@ -1000,7 +1001,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
if (kvm_x86_ops->set_cr4(vcpu, cr4))
return 1;
if (((cr4 ^ old_cr4) & pdptr_bits) ||
if (((cr4 ^ old_cr4) & mmu_role_bits) ||
(!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
kvm_mmu_reset_context(vcpu);